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// Copyright 2006-2008 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40285824): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif
#include "components/visitedlink/renderer/visitedlink_reader.h"
#include <stddef.h>
#include <stdint.h>
#include "base/check.h"
#include "base/functional/bind.h"
#include "base/metrics/histogram_functions.h"
#include "third_party/blink/public/common/features.h"
#include "third_party/blink/public/web/web_view.h"
using blink::WebView;
namespace visitedlink {
VisitedLinkReader::VisitedLinkReader() = default;
VisitedLinkReader::~VisitedLinkReader() {
FreeTable();
}
base::RepeatingCallback<
void(mojo::PendingReceiver<mojom::VisitedLinkNotificationSink>)>
VisitedLinkReader::GetBindCallback() {
return base::BindRepeating(&VisitedLinkReader::Bind,
weak_factory_.GetWeakPtr());
}
uint64_t VisitedLinkReader::ComputePartitionedFingerprint(
std::string_view canonical_link_url,
const net::SchemefulSite& top_level_site,
const url::Origin& frame_origin) {
// Ensure that we can determine a valid triple-partition key for this link. If
// invalid, we return the null fingerprint.
if (canonical_link_url.empty() || top_level_site.opaque() ||
frame_origin.opaque()) {
return 0;
}
// Determine the per-origin salt used for this fingerprint.
auto it = salts_.find(frame_origin);
if (it != salts_.end()) {
return VisitedLinkCommon::ComputePartitionedFingerprint(
canonical_link_url, top_level_site, frame_origin, it->second);
}
// If we cannot determine the per-origin salt, we cannot read the hashtable,
// so we must return the null fingerprint.
return 0;
}
// Initializes the table with the given shared memory handle. This memory is
// mapped into the process.
void VisitedLinkReader::UpdateVisitedLinks(
base::ReadOnlySharedMemoryRegion table_region) {
// Since this function may be called again to change the table, we may need
// to free old objects.
FreeTable();
DCHECK(hash_table_ == nullptr);
if (base::FeatureList::IsEnabled(
blink::features::kPartitionVisitedLinkDatabaseWithSelfLinks)) {
return UpdatePartitionedVisitedLinks(std::move(table_region));
}
return UpdateUnpartitionedVisitedLinks(std::move(table_region));
}
void VisitedLinkReader::UpdateUnpartitionedVisitedLinks(
base::ReadOnlySharedMemoryRegion table_region) {
int32_t table_len = 0;
{
// Map the header into our process so we can see how long the rest is,
// and set the salt.
base::ReadOnlySharedMemoryMapping header_mapping =
table_region.MapAt(0, sizeof(SharedHeader));
if (!header_mapping.IsValid())
return;
const SharedHeader* header =
static_cast<const SharedHeader*>(header_mapping.memory());
table_len = header->length;
memcpy(salt_, header->salt, sizeof(salt_));
}
// Now we know the length, so map the table contents.
table_mapping_ = table_region.Map();
if (!table_mapping_.IsValid())
return;
// Commit the data.
hash_table_ = const_cast<Fingerprint*>(reinterpret_cast<const Fingerprint*>(
static_cast<const SharedHeader*>(table_mapping_.memory()) + 1));
table_length_ = table_len;
base::UmaHistogramCounts10M(
"History.VisitedLinks.HashTableLengthOnReaderInit", table_length_);
}
void VisitedLinkReader::UpdatePartitionedVisitedLinks(
base::ReadOnlySharedMemoryRegion table_region) {
int32_t table_len = 0;
{
// Map the header into our process so we can see how long the rest is,
// and set the salt.
base::ReadOnlySharedMemoryMapping header_mapping =
table_region.MapAt(0, sizeof(PartitionedSharedHeader));
if (!header_mapping.IsValid()) {
return;
}
const PartitionedSharedHeader* header =
static_cast<const PartitionedSharedHeader*>(header_mapping.memory());
table_len = header->length;
}
// Now we know the length, so map the table contents.
table_mapping_ = table_region.Map();
if (!table_mapping_.IsValid()) {
return;
}
// Commit the data.
hash_table_ = const_cast<Fingerprint*>(reinterpret_cast<const Fingerprint*>(
static_cast<const PartitionedSharedHeader*>(table_mapping_.memory()) +
1));
table_length_ = table_len;
base::UmaHistogramCounts10M(
"History.VisitedLinks.HashTableLengthOnReaderInit", table_length_);
}
void VisitedLinkReader::AddVisitedLinks(
const std::vector<VisitedLinkReader::Fingerprint>& fingerprints) {
for (size_t i = 0; i < fingerprints.size(); ++i)
WebView::UpdateVisitedLinkState(fingerprints[i]);
}
void VisitedLinkReader::ResetVisitedLinks(bool invalidate_hashes) {
WebView::ResetVisitedLinkState(invalidate_hashes);
}
void VisitedLinkReader::UpdateOriginSalts(
const base::flat_map<url::Origin, uint64_t>& origin_salts) {
for (const auto& [origin, salt] : origin_salts) {
base::UmaHistogramBoolean(
"Blink.History.VisitedLinks.IsSaltFromNavigationThrottle", false);
AddOrUpdateSalt(origin, salt);
}
}
void VisitedLinkReader::FreeTable() {
if (!hash_table_)
return;
table_mapping_ = base::ReadOnlySharedMemoryMapping();
hash_table_ = nullptr;
table_length_ = 0;
}
void VisitedLinkReader::Bind(
mojo::PendingReceiver<mojom::VisitedLinkNotificationSink> receiver) {
receiver_.Bind(std::move(receiver));
}
} // namespace visitedlink
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